The genus Trigonotis comprises nearly 60 species mainly distributed in East and Southeast Asia.China has the largest number of Trigonotis species in the world,with a total of 44 species,of which 38 are endemic.Nutlet ...The genus Trigonotis comprises nearly 60 species mainly distributed in East and Southeast Asia.China has the largest number of Trigonotis species in the world,with a total of 44 species,of which 38 are endemic.Nutlet morphology is useful for the taxonomic delimitation of Trigonotis.However,there are still controversial circumscriptions of nutlet shape in some species.In previous studies,interspecies phylogenetic relationships were inferred using few DNA markers and very few taxa,which possibly led to erroneous or incomplete conclusions.In this study,the nutlet morphology of 39 Trigonotis taxa and the characteristics of 34 complete chloroplast genomes(29 taxa)were investigated and analyzed.Then,the phylogenetic relationships were discussed within this genus based on complete chloroplast genomes.To the best of our knowledge,this study is the first comprehensive analysis of nutlet morphology and complete chloroplast genome of Trigonotis.Based on nutlet morphology,Trigonotis can be divided into two groups:Group 1,hemispherical or oblique tetrahedron with carpopodiums,and Group 2,inverted tetrahedron without carpopodiums.The chloroplast genome of Trigonotis exhibited a typical quadripartite structure,including 84-86 protein-coding,37 transfer RNA,and 8 ribosomal RNA genes,with a total length of 147,247-148,986 bp.Genes in the junctions were well conserved in Trigonotis,similar to those in other Boraginaceae s.str.species.Furthermore,Trigonotis chloroplast genomes showed relatively high diversity,with more conserved genic regions than intergenic regions;in addition,we detected 14 hot spots(Pi>0.005)in non-coding regions.Phylogenetic analyses based on chloroplast genome data identified highly resolved relationships between Trigonotis species.Specifically,Trigonotis was divided into two clades with strong support:one clade included species with hemispherical or oblique tetrahedron nutlets with carpopodiums and bracts,whereas the other clade included species with inverted tetrahedron nutlets without carpopodiums or bracts.Our results may inform future taxonomic,phylogenetic,and evolutionary studies on Boraginaceae.展开更多
The achene wail anatomy and surface sculpturing of 14 species representing Lactuca L. and related genera were Investigated to evaluate inter-and Intrageneric relationships. The achene wall anatomy of the studied speci...The achene wail anatomy and surface sculpturing of 14 species representing Lactuca L. and related genera were Investigated to evaluate inter-and Intrageneric relationships. The achene wall anatomy of the studied species can be divided Into two types： winged and ribbed. The winged type is present in Lactuca L., Pterocypsela Shlh, Clcerblta Wallr., Chaetoserls Shlh and Stenoseris Shlh, and is characterized by protruding wings and costae in transverse section. Winged type achene mesocarps are composed of parenchymatous cells and fiber ceils, and the distinct fibrous strands are confined to the costae or wings of the achenes. The ribbed type is present in Notoseris Shih and Paraprenanthes Chang ex Shih, and Is characterized by only having costae In transverse section. Fiber cells are continuous in the costae and intercostae, in surface sculpturing, the ornamentation and the shape of epidermal cells are different among these genera. The results Indicate that L. altalca and L. serrlola should be conspeclfic, and that L. dollchophylla is probably an Intermediate taxon between Lactuca and Chaetoserls. The results also support the separation of Pterocypseia, Paraprenanthes, Notoseris, Chaetoseris and Stenoserls from Lactuca and Clcerblta as independent entitles. Close affinities between Pterocypsela and Lactuca, Paraprenanthes and Notoserls, and Chaetoserls and Stenoserls are also proposed.展开更多
基金This project was funded by the Science and Technology Basic Work,Ministry of Science and Technology,China(2013FY112100 to Q.L.)National Natural Science Foundation of China(31700175 to Z.W.)Fostering Project for Young Teachers of Zhengzhou University,China(JC21343014 to Z.W.).
文摘The genus Trigonotis comprises nearly 60 species mainly distributed in East and Southeast Asia.China has the largest number of Trigonotis species in the world,with a total of 44 species,of which 38 are endemic.Nutlet morphology is useful for the taxonomic delimitation of Trigonotis.However,there are still controversial circumscriptions of nutlet shape in some species.In previous studies,interspecies phylogenetic relationships were inferred using few DNA markers and very few taxa,which possibly led to erroneous or incomplete conclusions.In this study,the nutlet morphology of 39 Trigonotis taxa and the characteristics of 34 complete chloroplast genomes(29 taxa)were investigated and analyzed.Then,the phylogenetic relationships were discussed within this genus based on complete chloroplast genomes.To the best of our knowledge,this study is the first comprehensive analysis of nutlet morphology and complete chloroplast genome of Trigonotis.Based on nutlet morphology,Trigonotis can be divided into two groups:Group 1,hemispherical or oblique tetrahedron with carpopodiums,and Group 2,inverted tetrahedron without carpopodiums.The chloroplast genome of Trigonotis exhibited a typical quadripartite structure,including 84-86 protein-coding,37 transfer RNA,and 8 ribosomal RNA genes,with a total length of 147,247-148,986 bp.Genes in the junctions were well conserved in Trigonotis,similar to those in other Boraginaceae s.str.species.Furthermore,Trigonotis chloroplast genomes showed relatively high diversity,with more conserved genic regions than intergenic regions;in addition,we detected 14 hot spots(Pi>0.005)in non-coding regions.Phylogenetic analyses based on chloroplast genome data identified highly resolved relationships between Trigonotis species.Specifically,Trigonotis was divided into two clades with strong support:one clade included species with hemispherical or oblique tetrahedron nutlets with carpopodiums and bracts,whereas the other clade included species with inverted tetrahedron nutlets without carpopodiums or bracts.Our results may inform future taxonomic,phylogenetic,and evolutionary studies on Boraginaceae.
文摘The achene wail anatomy and surface sculpturing of 14 species representing Lactuca L. and related genera were Investigated to evaluate inter-and Intrageneric relationships. The achene wall anatomy of the studied species can be divided Into two types： winged and ribbed. The winged type is present in Lactuca L., Pterocypsela Shlh, Clcerblta Wallr., Chaetoserls Shlh and Stenoseris Shlh, and is characterized by protruding wings and costae in transverse section. Winged type achene mesocarps are composed of parenchymatous cells and fiber ceils, and the distinct fibrous strands are confined to the costae or wings of the achenes. The ribbed type is present in Notoseris Shih and Paraprenanthes Chang ex Shih, and Is characterized by only having costae In transverse section. Fiber cells are continuous in the costae and intercostae, in surface sculpturing, the ornamentation and the shape of epidermal cells are different among these genera. The results Indicate that L. altalca and L. serrlola should be conspeclfic, and that L. dollchophylla is probably an Intermediate taxon between Lactuca and Chaetoserls. The results also support the separation of Pterocypseia, Paraprenanthes, Notoseris, Chaetoseris and Stenoserls from Lactuca and Clcerblta as independent entitles. Close affinities between Pterocypsela and Lactuca, Paraprenanthes and Notoserls, and Chaetoserls and Stenoserls are also proposed.
